Death Wish or Just Inconsiderate?

I was on the all-too-familiar 4-lane Interstate today,(2 lanes each way) and as I approached one particular hill where most drivers pulled into the left lane to allow trucks entering the highway room to get up to speed. It also allows for other trucks (already on the highway) to gather a little speed in order to make it up the hill. There was a small economy car a couple cars ahead of me in the left lane also, not going quite as fast as the rest of us and a semi in the right lane. Now, granted the cars in the left lane were creeping up behind this small econo car, wishing it would move, but anyone with any common sense should know that you don't change lanes and get in front of a semi when it's trying to make it's way up a hill. Yet that is exactly what this driver did, pulled 'directly' in front of the semi, causing him to apply the brakes. Maybe that should be a question added to the Driver's License test...

It makes you ask the question:
Do they have a death wish, are they just plain inconsiderate... or stupid?